|장소||E6-2. 1st fl. #1323|
|일시||Oct. 18 (Tue.), 3PM|
|연사||Dr. JunHo Suh, Korea Research Institute of Standards and Science|
“Hybrid quantum systems with mechanical oscillators”
Dr. JunHo Suh, Korea Research Institute of Standards and Science
Oct. 18 (Tue.), 3PM, E6-2. 1st fl. #1323
Quantum machines are actively pursued to harness quantum coherence and entanglement as new resources for information processing and precision sensing. Among those activities, hybrid quantum systems are recognized as a promising platform for building multi-functional quantum machines by connecting quantum states in different physical domains, and mechanical oscillators are accepted as important components in the quantum hybrids. In this talk, I review recent examples of hybrid quantum systems involving mechanical oscillators strongly coupled to electrons and photons. In the first part, a quantum electro-mechanical system is introduced. A cooper-pair box qubit is electrostatically coupled to a nanomechanical oscillator. A dispersive measurement of qubit states is achievable through high-quality read-out of nanomechanical motion, which also maintains qubit coherence proved via microwave spectroscopy and Landau-Zener interference. In the second part, mechanical oscillators coupled to microwave photons, or "quantum opto-mechanical systems", are described, where radiation pressure mediates the interaction between photons and the mechanical oscillator. Photons act as a probe for mechanical motion in this case, and a fundamental limit in measurement sensitivity arises due to Heisenberg's uncertainty principle, as known as quantum standard limit(SQL). By carefully measuring mechanical motion in quadratures, we identify the fundamental back-action from photons which mandates SQL, and also demonstrate a novel scheme known as quantum non-demolition measurement (QND) which allows a precise measurement without back-action in one quadrature of motion. When the coupling between the microwave photons and mechanical motion is strong enough, the back-action from photons start modifying quantum noise in mechanical oscillators and produced mechanical quantum squeezed states[4,5]. Finally, it is expected that one could approach ultra-strong coupling regime as photon-mechanical oscillator coupling strength increases, where single photon coupled to mechanical motion dominates the hybrid system. Mechanical states in the ultra-strong coupling limit deviate from well-known number states which could open a new paradigm for controlling mechanical quantum states. A quantum dot system embedded in a nanowire is proposed to be a candidate to reach this interesting regime, and our recent progress toward this direction is dissussed.
 Kurizki et.al., PNAS 112, 3866-3873 (2015).
 LaHaye et.al., Nature 459, 960-964 (2009).
 Suh et.al., Science 344, 1262-1265 (2014).
 Wollman et.al., Science 349, 952-955 (2015).
 Lei et.al., PRL 117, 100801 (2016).
 Nation et.al., PRA 93, 022510 (2016).
Contact: SunYoung Choi, (firstname.lastname@example.org)
Center for Quantum Coherence in Condensed Matter, KAIST
|336||2019/09/18 - 12/5||Seminar Room #1323||Prof. David Schuster and etc.||Fall 2019: Physics Seminar Serises|
|335||2019/09/02 - 12/09||Seminar Room 1501||이호성 박사 (한국표준과학연구원) and etc.||Fall 2019: Physics Colloquium|
|334||Sep. 24(Thu), 09:00~, Sep. 24(Thu), 16:00 ~||Zoom Video||Akash V. Dixit (University of Chicago), Dr. Boris Ivanov (Novosibirsk State Technical University)||(CAPP/IBS)Searching for Dark Matter with a Superconducting Qubit , Cryogenic Microwave Circuit Development at the NSTU|
|333||Jan.28(Thu), 06:00PM||Online Seminar||Alexandre Zagoskin(Loughborough Univ.)||Quantum metamaterials: concept, theory, prototypes and possible applications|
|332||2015/12/09, 11AM||E4(KI Building), Connect room (2nd fl.)||Arjun G. Yodh (University of Pennsylvania)||Functional Imaging & Monitoring of Brain & Breast with Diffuse Light|
|331||2015/12/09, 2PM||E6-2, #1323||Arjun G. Yodh (University of Pennsylvania)||SWELLABLE COLLOIDAL PARTICLES ARE SWELL|
|330||Sep.28. 5:30 pm||Zoom webinar||Burkard Hillebrands (TU Kaiserslautern, Germany)||KAIST Global Forum for Spin and Beyond(Fourth Forum)|
|329||Apr. 19(Mon) 19:00||Zoom webinar||Chia-Ling Chien (Johns Hopkins, USA)||Evidence of Electrical Switching in Antiferromagnets and Coherent Spin Pumping|
|328||Thursday, December 14, 2017 at 3:00 pm||Seminar Room (C303), Creation Hall (3F), KAIST Munji Campus||Chunglee Kim (KASI)||Exploring the Universe via GWs in the era of multi-messenger astronomy|
|327||Oct. 25 (Fri), 15:00 ~||#1323, E6-2||Daesu Lee,Junwoo Son,MyungJoon Han ,Siheon Ryee,Eun-Gook Moon||Physics Seminar|
|326||Dec. 12th (Mon)||1:30p.m. #1323(E6-2. 1st fl.)||Dongjoon Song , AIST||“Possible symmetry in the phase diagrams of electron- & hole-doped cuprate high-Tc superconductors”|
|325||April 6, 2016 (Wed), 3:30 PM||E6-2, RM #1323||Dr. Andrei Matlashov (Los Alamos National Laboratory)||Superconducting Quantum Interference Devices for Precision Detection|
|324||Apr. 5 (Tue.), 4PM||E6-2. 1st fl. #1322||Dr. Ara Go, Columbia University||A new impurity solver for multi-orbital systems: adaptive truncation of the Hilbert space|
|323||2016/1/11, 4PM||E6-2, #1323||Dr. B.J.Kim (Max Planck Institute for Solid State Research)||Mott Physics in the Strong Spin-Orbit Coupling Regime|
|322||Nov. 11th (Fri), 4 p.m.||#1323(E6-2. 1st fl.)||Dr. Bohm-Jung Yang, SNU||Dirac fermions in condensed matters|
|321||Jun 28, 14:00||E6-2, #1322||Dr. Bongjae Kim, Dr. Sooran Kim, Dr. Jeongwoon Hwang||1st Research-exchange meeting of computational material physics|
|320||May 11 (Wed.), 4 PM||E6-2. #1323(1st fl.)||Dr. Bumjoon Kim, Max Planck Institute for Solid State Research||The quest for novel high-temperature superconductors---Prospects and progress in iridates|
|319||Feb. 12 (Mon), 3:00pm||#C303, (Creation Hall 3F, KAIST Munji Campus)||Dr. Byeongsu Yang, Kamioka Observatory, Univ. of Tokyo||The recent result of XMASS Experiment|
|318||JAN. 7 (Mon), 03:00 PM||E6-2. 2st fl. #2501||Dr. Byoung min Kang||Many-Body Invariants for Multipoles in Higher-Order Topological Insulators|
|317||Oct. 18 (Tue.), 1:30 PM||1st fl. #1323(E6-2)||Dr. Chan-Ho Yang, Department of Physics, KAIST||"Visualization of oxygen vacancy in motion and the interplay with electronic conduction"|